The present invention relates to an orthodontic device for use in repositioning teeth within the mouth of a patient. More particularly, the present invention is concerned with an orthodontic device which may be attached to orthodontic brace wires connected to teeth of the upper and lower jaw, or between teeth of the same jaw, for the purpose of applying a constant calibrated force to the teeth so as to cause the teeth to change position within the mouth over a period of time.
Previous spring operated devices for use in moving teeth within the mouth of a patient have included the devices described in the following Holmes U.S. Pat. Nos. 360,695 ; 3,618,214 to Armstrong; 3,798,773 to Northcutt; and 4,259,065 to DeWoskin.
The Holmes patent discloses a spring regulating appliance which is attached between a tooth and a securing position on a temporary plate applied to the palate or roof of the mouth. The Armstrong patent discloses the use of plurality of coiled springs which are telescoped together and secured to a pair of eyelets for engagement with hooks on orthodontic arch wires. The Northcutt patent discloses a compression device for use in realignment of the teeth which includes a pair of ring and telescopic tube arrangements which in one embodiment may be attached directly to the brace wires on the upper and lower jaw. The DeWoskin patent discloses traction apparatus having a pair of side members to be worn on opposite sides of the patient's head. Each side member has a tensioning assembly which includes a spring mounted within a tube.
Devices for locking various appliances on a brace or arch wire include that described in U.S. Pat. No. 3,238,619 to Brunson et al. wherein an arch wire locking device for an orthodontic bracket affixed to a tooth band is disclosed in which the arch wire is retained within a slot in the casing of the bracket.
It is an object of the present invention to provide an improved orthodontic device which may be attached directly to the orthodontic brace wires on the upper and lower jaw, or between teeth of the same jaw, for use in repositioning teeth.
It is an additional object of the invention to provide an orthodontic device which is of compact construction for use in moving teeth within the mouth of a patient.
It is a further object of the invention to provide an orthodontic device which is constructed so as to be comfortable in the mouth of a patient and to eliminate various discomforting features of prior art devices.
It is an additional object of the present invention to provide an orthodontic device which remains installed and activated throughout each 24 hour day and functions to reposition the teeth, while not interfering with chewing or other normal functions of the mouth.
It is another object of the invention to provide continual application of previously determined corrective forces for the purpose of changing the position of one or more teeth within the mouth of a patient.
It is a further object of the invention to provide an orthodontic device which is of relatively simple construction, thus facilitating installation and use of the device in the mouth of a patient.
The foregoing as well as additional objects are obtained by the orthodontic device of the present invention in the form of a calibrated spring module which is particularly well suited for the purpose of moving teeth with a constant calibrated force. The spring module device includes a telescope mechanism having inner plunger portion and outer tube portion, and with resilient means which may be in the form of a calibrated compression coil spring concentrically positioned on the inner telescope plunger portion within the telescope outer tube portion. The spring is longitudinally retained between a notched end wall of the telescope tube and a flange on the inner end of the telescope plunger portion such that, in the operative position, the telescoped members are spring biased so as to be urged to a retracted condition.
In one embodiment, the telescope mechanism is attached to brace wires located on teeth of the upper and lower jaw or on teeth of the same jaw by the use of a ball and socket mechanism at one end of the device and a birfurcated yoke at the opposite end. The ball and socket mechanism, which is attached to the tube portion of the telescope mechanism, is provided with an anchor pin or trunnion member extending inwardly of the socket and a flat plate member attached to the inner end of the anchor pin and extending generally perpendicular to the longitudinal axis of the anchor pin. A radial slot is provided between the anchor pin and the plate member for receiving an arch or brace wire. A screw member extends through the anchor pin to retain the arch wire in the slot.
At the opposite end of the device, the bifurcated yoke is attached to the outer end of the plunger portion of the telescope mechanism. The yoke has a pair of lug portions adapted to receive between them an arch wire. A tie wire extends through respective bores in the lugs to effectively enclose the arch wire between the lugs and the tie wire.
In using the spring module, the attachment members at either end of the device are secured to orthodontic means and fixed in the desired location on the teeth. Upon attachment of the yoke and the ball and socket member in position so that the spring is compressed, the device is then in an activated condition for use in moving teeth with a constant calibrated force. The spring may be calibrated to return to its original dimension with a specific force such as approximately four to six ounces.
The characteristic features of the present invention include the feature whereby an enclosed coiled spring is installed in a compressed condition within a telescope mechanism and positioned between teeth either of the same jaw or of the upper and lower jaw in such a manner that spring bias force tends to pull teeth toward each other. An additional feature of the present invention resides in the baised unit having a ball and socket member attached to the tube portion of a telescope mechanism, and with a bifurcated yoke attached to the outer end of the plunger portion of the telescope mechanism, wherein the plunger rod is bent to form an angle which effectively prevents the device from contacting orthogontic means previously installed in the mouth of a patient, while allowing freedom of movement of the telescope mechanism during use within the mouth of the patient.
A primary feature of the invention is the use of a compressed coiled spring extending axially within the telescoped member with the spring being calibrated to exert a known force on one or more teeth as it seeks to expand to its original dimension. The present invention has been found to be particularly effective in repositioning the canine and cuspid teeth as well as the six front teeth of either jaw as a group.